Flow control method and apparatus



Nov. 23, 1965 R. o. WALTON 3,218,985

FLOW CONTROL METHOD AND APPARATUS Filed Sept. 3, 1963 4 Sheets-Sheet 1 3 v, 0 M L W R 5 W a W M 3 a 1m 4 wmv J ma U f ,4, My, 3 WW A i s W/ :0 5 O M 7. 7 m w w 9 0 4L 3 3 N fih 2M2.\wQ m m v 4w v F. mm a f *6? x3 Nov. 23, 1965 R. O. WALTON FLOW CONTROL METHOD AND APPARATUS Filed Sept. 3, 1963 4 Sheets-Sheet 2 Nov. 23, 1965 R. 0. WALTON FLOW CONTROL METHOD AND APPARATUS 4 Sheets-Sheet 3 Filed Sept. 5, 1963 Z m M HTI'O/P/VEY Nov. 23, 1965 R. o. WALTON 3,218,985

FLOW CONTROL METHOD AND APPARATUS Filed Sept. 3, 1963 4 Sheets-Sheet 4 Juuu INN

4 INVENTOR. fioerf 0. Wa/zafl ATTORNEY United States Patent F 3,218,985 FLOW CONTROL METHOD AND APPARATUS Robert O. Walton, Odessa, Tex., assignor to Merla Tool Corporation, Garland, Tex., a corporation of Texas Filed Sept. 3, 1963, Ser. No. 306,192 22 Claims. (Cl. 103-232) This invention relates to flow control methods and means for wells and consists, particularly, in novel methods and apparatus for controlling the flow of a fluid, such as lifting gas, from the annulus into the production tubing of an oil well.

Previous gas lift systems for inducing production from low pressure oil Wells have required the incorporation in the tubing string of judiciously spaced flow valve devices which may respond either to (1) predetermined tubing pressure, or (2) predetermined annulus pressure, or (3) the differential between such pressures for opening the flow valve to admit lifting gas. All of these systems require reasonably accurate knowledge of tubing pressures and corresponding control of the annulus gas pressure. Frequently, the obtaining of such information is difiicult or impossible as is the maintaining of exact gas pressure conditions. The result may be wastage of gas due to excess gas supplied in order to err on the safe side, or blockage which may occur when the liquid level in the tubing rises to a level higher than can be handled by the lifting equipment provided. Furthermore, the space requirements of such gas lift devices have limited their use, particularly in multiple string wells. Another disadvantage of such devices has been that in order to reset the same for different tubing and/ or annulus pressure conditions, it has been necessary to withdraw the entire string to gain access to the lift valve devices.

According, it is an object of the present invention to provide a flow valve, particularly of the gas lift type, which may be inserted into the tubing string when it is initially run and which, however, does not affect the normal functioning of the string nor have excess space requirements.

Another object is to provide a flow control system having a separate actuator for such a valve which may be run in the well when it is desired to commence flow or gas lift operations.

Another object is to provide a flow valve system of the above type in which control features can be readily recovered without the necessity of withdrawing the tubing string, for instance, for the purpose of adjusting the pressure setting of the device.

Another object is to provide a gas lift system incorporating an actuator device which includes tubing pressure sensing means capable of rendering the actuator operative to control a flow valve only when tubing pressure conditions in the vicinity of that valve warrant the opening thereof. a

In accordance with the present invention, a production tubing string is provided with one or more flow valve devices of the slave type which, normally, are closed so as to prevent the transfer of annulus fluid into the tubing and which do not unduly extend the exterior thereof or obstruct the interior of the tubing for the running of tools. A pilot valve is provided in connection with the flow valve which has an actuator element exposed interiorly of the tubing string. A separate actuator device is provided which can be run into the tubing string and which, upon being exposed to predetermined pressure conditions, will expand in such a way as to engage and actuate a pilot valve abreast thereof to initiate flow through the main flow valve. Preferably, the actuator will be automatically shifted, after the flow of gas during a predetermined time interval, to cut off such flow, and then, after a further time interval, to restart the gas flow for intermitting effect, as long as the tubing head pressure 3,218,935 Patented Nov. 23, 1965 to which the actuator is exposed equals or exceeds the predetermined pressure for which the actuator is set. The actuator may be dropped through the tubing string, past any number of flow valves until it reaches the vicinity of a valve where the tubing head pressure conditions would justify the supply of lifting gas. The control of the actuator may be entirely subsurface or may be from surface-mounted timing and other control instrumentalities.

In the accompanying drawings which illustrate the invention,

FIG. 1 is a largely schematic sectional view showing portions of an oil well having the novel flow control system incorporated therein.

FIG. 2 is an enlarged vertical transverse section illustrating a portion of the surface control of the actuator.

FIGS. 3 and 4 are enlarged, vertical transverse center sections illustrating a flow valve and actuator device in operative juxtaposition, the actuator device being shown in different operative conditions.

FIG. 5 is a horizontal section taken substantially on line 5-5 of FIG. 3.

FIGS. 6 and 7 are detailed vertical sections illustrating different forms of flow valves.

FIG. 8 is a vertical transverse section illustrating another form of the invention.

FIG. 9 is a view similar to FIG. 8, but showing the actuator in a different operative condition.

FIG. 10 is an enlarged detail of the structure in FIGS. 3 and 4.

FIG. 1 shows an oil well having a casing 12 extending to a producing formation 13 and therein provided with perforations 14. Within the casing there is provided a production tubing string, generally designated 15, which depends from the casing head 16 and is provided at intervals along its length with flow valve devices, generally designated 17, 18 and 19. The annulus 20 is packed off at 21 just above the producing formation and the tubing is provided at its lower extremity with production perforations 22 and a foot valve 23. A pipe 24 connects with the well annulus above the ground level for supplying pressured lifting gas thereto. The tubing string comunicates through a delivery pipe 25 with separator or other treating and storage facilities.

Landed upon lugs 28 adjacent a lower flow valve 19 is an actuator generally designated 29 to be hereafter more fully described. Another actuator device 30 of generally similar construction is suspended on a wire line cable 32 which depends through the casing head and Christmas tree elements including a control device 33. This wire line extends around a guide sheave 34 thence to a winch 35 having a friction let-out braking arrangement conventionally designated 36.

FIG. 2 illustrates the wire line control device 33. As illustrated, this device includes a housing 40 forming a cylinder 41 in which works a sealed piston 42 having a tubular stem 43 slidably received in a packed axial opening 44 in end wall 45 of the cylinder. Extending beyond end wall 45 is a housing portion 46 having an annular collar 47 at its upper extremity with a downwardly and outwardly tapered outer surface 48. Received upon collar 47 is a collet chuck including segments shaped in section as illustrated at 49 and 50. Each segment has a depending peripheral flange 51 with a downwardly and outwardly inclined inner surface 52 which rests upon complementary surface 48 of collar 47. Wire line 32 extends through the axial opening 53 in the chuck and also through an axial orifice 54 in piston stem 43 and an aligned opening in bottom wall 55 of cylinder 41. Orifice 54 and the opening in wall 55 are provided with packings 56 and 57 for sealingly but slidably receiving the wire line.

At the upper end of piston stem 43 there is provided an inverted conical recess 58 which is complementary to the inclined outer surfaces 59 of the central portions 60 of the chuck segments. This arrangement is such that when piston 42 and stem 43 are elevated, recess 58 engages chuck portions 60 so as to cause the chuck device to firmly grip the wire line. When the piston and stem are lowered, the chuck segments are permitted to drop and are urged radially outwardly by mating surfaces 48 and 52. Piston 42 is actuated by fluid pressure supplied through conduits 61 and 62 from a control device conventionally represented at 63. Device 63 incorporates timing means or means responsive to variations of pressure at the delivery end of the production tubing for controlling wire line 32 and the suspended valve actuator 30, as will be described.

The flow valves 17, 18, and 19, preferably, are alike, and may be as illustrated in FIGS. 3 and 4. Incorporated in the tubing string at desired positions therealong are flow valve housings, generally designated 65 and each having box and pin joints at its ends (not shown) for threaded attachment to mating joints at the ends of adjacent tubing sections. Intermediately, the housing has spaced concentric walls 66 and 67 provided, respectively, with ports 68 and 69. If desired, groups of these ports may be provided communicating respectively with well annulus 20 and the interior of the housing and tubing string. A sleeve valve 70 of suitable resilient material has its ends secured to housing walls 66 and 67, as at 71 and 72, and divides the space between the housing walls into a first chamber 73 communicating through ports 68 with the well annulus and a second chamber 74.

Beneath flow valve chamber 74, the housing is provided with an internal annular recess 75 within which is pivoted at 76 a semi-circular pilot valve actuating element 77. Element 77, normally, lies within recess 75 so as not to obstruct the interior of the housing and the tubing string. Housing 65 adjacent element 77 is provided with a pilot valve chamber 78 (FIG. 10) which communicates through a passageway 79 with lower flow valve chamber 74. Small valve chamber 78 is connected to the well annulus through a port 80 and with the interior of housing 65 and the tubing string through an aligned port 81. Loosely extending through this latter port is the actuator stem 82 of a pilot ball valve 83 within chamber 78. At the end of stem 82 is a head 84 normally urged by a small coiled spring 85 against half-circle pilot actuator member 77. Thus, in the normal position of the pilot valve, as in FIGS. 3 and 10, annulus pressure will be transmitted through port 80 and passageway 79 to lower flow valve chamber 74. Likewise, annulus pressure will be transmitted through ports 68 to upper flow valve chamber 73. Since the pressures across the flow valve will be balanced, the valve will be urged into its closed position against ports 69 by a coiled, radially resilient spring 86.

FIGURES 6 and 7 show other forms of flow valves for cooperating in a similar manner with a pilot valve as heretofore described. Both of the modified flow valves are intended for mounting on the exterior of a tubular housing which is inserted in the piping string. In FIG. 6, a small tubular housing member 88 is threadedly secured at its upper end to a lug 89 which may be welded in position on housing 90 inserted in the tubing string. Within housing member 88 there is provided a valve chamber 91 within which slides a packed plunger 92 constantly urged upwardly by a coiled compression spring 93 resting on a centrally apertured ledge 94. A stem 95 projects upwardly from plunger 92 and has a valve forming head 96 at its upper end for seating against the lower end of a passageway 97 formed in welded lug 89. Valve chamber 91 communicates with the well annulus through ports 98.

A chamber 99 in the lower part of housing portion 88 communicates at its lower end through a tube 100 with a passageway 101 which connects with pilot valve chamber 102 containing a pilot valve 103 actuated by semicircular actuator element 104, as in the previous form. Port 105 connecting pilot valve chamber 102 with the well annulus is provided with an adjustable metering valve, conventionally shown at 106, for a purpose to be described.

When pilot valve 103 is in its normal position, as shown, lower flow valve chamber 99, 93 will communicate with the well annulus, as will upper flow valve chamber 91. Under these conditions, flow valve 96 will be held closed by spring 93. When pilot valve 103 is shifted to close port 105, tubing pressure will be applied to chamber 99 so that the annulus pressure applied in chamber 91 will cause opening of the flow valve.

FIG. 7 shows still another form of slave type flow valve including a housing cap 107'which is bolted or otherwise fastened to a pad 108 secured as by welding to the tubular housing portion 109 which is threadedly inserted in the tubing string. A flexible diaphragm 110 clamped in position by cap 107 has a central valve-forming part 111 which is urged by a coiled spring 112 into normal seating position against the end of a nipple 113 mounted in housing portion 109 centrally of pad 108. Space 114 around the nipple and inside the diaphragm valve is connected by ports 115 to the well annulus. Cap 107 is extended downwardly by a tubular part 116 threadedly secured thereto and the hollow interior 117 of part 116 is connected by a tube 118 and passageway 119 to pilot valve chamber 120.

Actuator device 30, as shown in FIGS. 3 and 4, comprises an upper body part 121 from which projects the fishing neck 122 and through which extends a central orifice 123 with an enlarged lower part 124. Wire line 32 extends through orifice 123 and has as its end a catch ball 125 lodged against the shoulder formed between orifice portions 123 and 124 to support the actuator device.

Intermediate body portion 126 of the actuator device is threadedly secured at 127 to upper body portion 121 and has a central passageway 128 which merges with outward radial grooves 129 (FIG. 5). Threadedly secured to the lower wall 130 of the intermediate body portion is a cup-shaped housing portion 131 to the lower wall 132 of which there is secured a collapsible and expansible bellows or capsule 133 which is provided with a gaseous charge admitted through valve controlled filling opening 134. Chamber 135 receiving the capsule communicates through orifices 136 with the interior of the tubing string. Projecting upwardly from capsule 133 is a stern 137 which is slidably received in body wall 130 and also in enlarged axial orifice part 124 of upper body member 121.

Pivotally secured to stem 137 just above radial slots 129 in body portion 126 and disposed in quadrature about the stem are pilot valve actuating fingers 139. These fingers normally hang in the collapsed position of FIG. 3 entirely within the confines of body portion 126 to permit the actuator device to be run into a tubing string. However, when capsule 133 is compressed, as in FIG. 4, stem 137 is drawn downwardly, moving fingers 139 against pins 140 traversing passageway 128 so as to cause the fingers to pivot outwardly or expand. If and when the expanded fingers are positioned abreast of a pilot actuator element 77, this element will be correspondingly shifted outwardly so as to reverse the associated pilot valve and open the main flow valve. The inclined lower ends of the fingers insure passage thereof inside of half ring elements 77.

Depending from capsule housing 131 is a weight bar and fishing socket member 140. This member must be readily removable, or alternatively, access must be provided therethrough, for charging capsule 133. At its lower end, member 140 is provided with a recess 141 having hooks or detents 142 pivotally mounted on the wall thereof for attachment to a fishing neck 122, as shown in dotted lines, when the socket is dropped thereover. Such socket structure may be omitted from the weight bar 143 which depends from lower actuator device 29 (FIG. 1).

The above described apparatus operates as follows: With flow valves incorporated into the production tubing string, as at 17, 1-8 and 19, a first actuator device 29 will be lowered on a wire line to rest against a suitable stop, as ledge or lugs 28, abreast the lowermost flow valve 19. The purpose of this actuator device is to provide an opening into the tubing above packer 21 through which annulus liquid may be forced into the tubing when the annulus is charged with lifting gas. Accordingly, capsule 133 of actuator device 29 will be charged such that the tubing head pressure existing adjacent flow valve 19 will collapse the capsule and expand operating fingers 139 of this actuator so as to act through the associated pilot and main flow valves to open the flow path through ports corresponding to ports 68 and 69 of FIGS. 3 and 4. Thereafter, annulus 20 of the well will be charged with lifting gas at the desired pressure, as determined by pres sure conditions in the tubing.

Next, the wire line will be disconnected from lowermost actuator 29 and an actuator device 30 lowered thereby through the control structure 33 and into the tubing. Capsule 133 of device 30 will be charged at the surface so as to cause expansion of its actuator fingers when the well pressure head applied thereto is sufiicient to insure most effective use of lifting gas at a particular depth of liquid. Brake device 36 is set so that the weight of the actuator device will cause pay out of the wire line and continued lowering of the actuator device until it reaches a region where the liquid pressure head in the tubing is suflicent to compress its capsule 133 and expand its actuator fingers 139. Thereafter, the actuator device will continue to lower until its fingers 139 enter the next lower annular recess 75 associated with a flow valve. At this point, one or more of the actuator fingers will engage semi-circular pilot actuating element 77 to shift the same and corresponding pilot valve 83 outwardly in the manner as explained above to cut off lower flow valve chamber 74 from the annulus pressure and connect this chamher to the tubing pressure. The main flow valve then opens permitting the flow of lifting gas from the annulus into the interior of the tubing string through ports 68 and 69. The gas then rises in the tubing string, carrying a slug of liquid with it in the well known manner.

When pilot actuating fingers 139 enter the flow valve recess 75, the lower ends thereof rest against the lower edge of the recess so as to support the weight of the actuator device. Accordingly, stoppage of payout winch 35 creates a signal which is transmitted through line 150 to wire line control apparatus 63. This signal starts a timing device which, after a predetermined time interval, applies fluid pressure through line 62 beneath plunger 42. Thereupon, the plunger and stem 43 are elevated and, ultimately, mating wedging surfaces 58 and 59 will cause gripping of the wire line by the collet segments 49, 50, etc. Continued upward movement of the plunger will lift the wire line and suspended actuator device 30 so as to clear pilot actuator half ring 77 and permit closing of the pilot and flow valves. Thereupon, control device 63 will reverse the application of fluid pressures to plunger 42 to lower the plunger, after a further time interval, returning the actuator device 30 to its position with its actuator fingers abreast the particular pilot valve actuator 77. If the tubing pressure head in this region continues sufiiciently high, fingers 139 will have remained expanded and the flow valve will be reopened to repeat the timed cycle of intermittent gas lifting.

When sutficient liquid above the particular flow valve being considered has been removed so that the tubing pressure head adjacent this flow valve will be insufficient to cause expansion of actuator fingers 139, actuator device 30 will pass this particular flow valve and will continue its descent until a sufiicient tubing pressure head is reached for collapsing capsule 133 and expanding the actuator fingers, as described. The timing cycle, of

6 course, can be adjusted at the surface. Likewise, the charge in capsule 133 may be corrected by returning the actuator device to the surface, while the production tubing remains in position with the flow valves closed. Ultimately, actuator device 30 may latch onto lower actuator 29 where it will continue to function as long as it is left in position and may be recovered therewith, if desired.

The form in FIGS. 8 and- 9 involves pilot and flow valves as heretofore described, and these parts are given the same reference numerals as in FIGS. 3 and 4. This device includes an upper body including an enlarged upper part 152, which is freely slidable within the interior of flow valve housing 65, and a reduced lower portion 153, having a continuous central orifice 164 therethrough which slidably receives a stem 165 having a fishing head 166 at its upper extremity. An intermediate body part 167 is threadedly secured at 168 to the upper body part and has a central passageway 169 in which is slidably received a plunger 170 formed on stem 165. A coiled spring 171 is compressed between plunger 1'70 and the bottom of the upper body part. The pilot valve actuating fingers 172 are pivotally secured at 173 to stem 165 and cross pins 174 are provided, as in the previous form, for causing expansion of the fingers. Stem 165 at its lower end is secured to a charged bellows or capsule 175 mounted in a cup-shaped housing 176 secured to the lower end of the intermediate body part. Capsule chamber 177 communicates through ports 178 with the interior of the tubing string so as to be subjected to the pressure therein. A weight bar 179 depends from capsule casing 176 and may be provided with a fishing socket, as in the previous form.

A catcher device 182 is mounted or supported in the tubing string at a suitable point above the actuator device after it is inserted. For convenience, this device is shown mounted at the surface, but may be mounted at any intermediate point, including just sufiiciently above the actuator to permit closing of the flow valve, as will be explained. The catcher includes detent elements 183 pivoted to a suitable support 184 and pinned at their upper ends to parallel links 185 and 186 which, in turn, are pinned at their inner ends to a control bar 187. Bar 187 is pivoted on support 184 and is connected by a stem 188 to a timer device 189 and is constantly urged against a stop 190 by a coiled spring 191. The timer device is designed to cause release of a caught fishing head, as 166, a predetermined time interval after detents 183 catch the head.

This form of the invention operates as follows: With flow valve housing 65 incorporated at desired positions in a production tubing string, a first actuator device may be landed above the production formation, as in case of the actuator 29 in FIG. 1. The well annulus is then charged with lifting gas, as previously. Capsule 175 of a second actuator device is then charged at a pressure for causing actuation of a flow valve at an optimum depth in the well liquid for gas lift operations. The second actuator is then dropped into the tubing, no wire line being needed in this case. Immediately, a catcher device 182 is mounted or suspended in the tubing above the second actuator, and timer 189 is adjusted to provide the desired intermittent gas lift operation. When the second actuator device has dropped in the tubing to the point where the tubing head pressure is sufficient to contract bellows 175 and expand pilot actuating fingers 172, these fingers will enter the next lower flow valve recess 75 for actuating the corresponding pilot valve and thereby opening the slave flow valve 70. As annulus gas is admitted through ports 68 and 69 and rises within the tubing, it applies a pressure differential to the enlarged body part 152 which will lift the actuator device bodily, first clearing the pilot valve and, ultimately, causing engagement of fishing head 166 by the catcher device.

Since it is necessary that the flow of lifting gas into the tubing continue long enough to cause the actuator to be engaged by the catcher, orifice 80 between the annulus and the pilot valve chamber will be restricted so as to delay the equalization of pressures across the flow valve 70. If desired, an adjustable valve may be provided in orifice 80, as at 105 in FIG. 6. Pilot actuating fingers 172, of course, will remain expanded until the actuator enters a region in the tubing where the pressure head is insufficient to contract the bellows. After the predetermined time interval, the actuator device will be dropped by the catcher, and will descend, as before, until the expanded actuator fingers 172 are caught within a flow valve recess 75.

If desired, catcher 182 may be located just sufiiciently above the working fiow valve to permit the travel of the actuator which is required to release the pilot. In this situation, of course, the upper actuator device will have a relatively short stroke and gas passing around the upper body member may be utilized to do the actual lifting. On the other hand, the actuator device may be permitted to lift to a greater extent or even to the surface to provide, in effect, fluid actuated piston action.

Various types of flow valves may be provided, for instance, as shown in FIGS. 6 and 7, and if desired the fiow valve may be directly actuated, rather than through a pilot valve. In all forms, the actuator may be readily recovered for adjustment to different gas lift conditions or for terminating the gas lift operation. Also, it is contemplated that the separate actuator may be utilized in connection with other types of fiow control, for instance, the regulation of the pressure of oil entering the tubing string from a high pressure formation. The actuator fingers may be formed of resilient material welded or otherwise secured to the actuator stern and adapted to be flexed to the collapsed or expanded position. The invention may be modified in various respects as will occur to those skilled in the art, and the exclusive use of all modifications as come within the scope of the appended claims is contemplated.

I claim:

1. The combination with well production tubing having ports through the wall thereof at intervals therealong of a valve controlling each of said ports and a valve actuator device received in said tubing and normally movable therealong past said valves, said device including mechanism for engaging and opening said valves selectively during movement along said tubing and means operatively connected to said mechanism and responsive to predetermined ambient tubing pressure for causing said mechanism to open the one of said valves exposed to said predetermined pressure.

2. The combination with well production tubing having ports through the wall thereof spaced therealong of normally closed valves mounted in the tubing wall and respectively controlling said ports and a valve actuator device received in said tubing and movable therethrough past said valves, said device including a part movable for opening the one of said valves in juxtaposition therewith and tubing pressure sensitive means adjacent and operatively connected to said part for moving the same to open the one of said valves exposed to said predetermined tubing pressure.

3. The combination with a well production tubing string having a port through the Wall thereof, of a valve controlling said port and having an inwardly exposed actuator element and a valve actuator device comprising a body slidable through the string, a stem slidably mounted longitudinally in said body, an actuator finger operatively connected to said stern and shiftable radially thereby between an inoperative position within the confines of said body and a valve opening position projecting radially beyond said body for shifting said actuator element, and means for shifting said stem to move said finger between said positions.

4. The combination with a production tubing string having a port through the wall thereof, of a valve controlling said port and having an inwardly exposed transversely movable actuating element and an actuator device comprising a body of a size and shape to be run through the tubing past said valve, an axial passage in said body, a stem slidably mounted longitudinally in said body, slots extending radially from said passage through said body, actuator fingers in said slots and pivotally secured to said stem, and camming elements engageable by said fingers during movement of said stem in one direction for causing said fingers to project beyond said body in position to engage and shift said actuating element.

5. The combination as described in claim 3 in which said stem shifting means comprises means operatively connected to said stem and responsive to predetermined tubing head pressure for shifting said stem and finger to their valve opening positions.

6. The combination as described in claim 5 in which said means comprises a fluid charged capsule operatively connected to said stem and exposed to tubing pressure in the vicinity of said finger, said capsule being compressible by predetermined tubing head pressure for shifting said stem and said fingers to their valve opening positions.

7. Flow control apparatus for well production tubing comprising a housing for insertion in the tubing, a check valve device in said housing dividing the same into first and second chambers, passageways connecting said first chamber, respectively, with the interior and exterior of the tubing, means normally urging said valve device toward a closed position for preventing communication through and between said passageways, other passageways connecting said second chamber, respectively, with the interior and exterior of the tubing, a pilot valve controlling said other passageways, and actuator mechanism for said pilot valve located within said tubing for selectively exposing said second chamber to pressure conditions inside and outside of the tubing.

8. Flow control apparatus as described in claim 7 in Which said actuator mechanism includes a stem extending from said second chamber through one of said other passageways into said housing and a device inside said housing for actuating said stem.

9. Flow control apparatus as described in claim 8 further including means for shifting said actuating mechanism to and from its operative position in juxtaposition with said stem.

10. Tubing fiow control apparatus as described in claim 7 in which said check valve device is formed by a flexible wall member exposed on opposite sides to said chambers and thereby responsive to differential pressure conditions therein for selectively opening and closing communication through and between said first mentioned passageways.

11. Flow control apparatus as described in claim 8 in which said actuator mechanism includes a radially movable part positioned to actuate said pilot valve stem and means responsive to predetermined pressure conditions in the tubing in the vicinity of said part operatively connected to said part for shifting said part and said pilot valve to expose said second chamber to said tubing pressure.

12. Flow control apparatu as described in claim 8 in which said actuator mechanism includes a radially movable part positioned to actuate said pilot valve stem and timed means for actuating said radially movable part and said stem.

13. Flow control apparatus as described in claim 8 in which said actuator mechanism includes a radially movable part positioned to actuate said pilot valve stem, timed means for periodically urging said part in the direction for actuating said pilot valve stem, and means responsive to predetermined pressure conditions in the tubing for preventing stem actuating movement of said part until said predetermined pressure conditions exist.

14. Gas lift control means for a cased well having a tubing string extending to a production zone and a gas pressured annulus comprising a housing inserted in the tubing string, a flow passage through the wall of said housing, normally closedvalve means controlling said passage and having an actuating element exposed inwardly of said housing, a valve actuator device in said housing, said device including a radially movable part for engaging said element and means responsive to predetermined pressure conditions in the tubing string for shifting said part outwardly from a position to clear said element to a position for engaging and actuating said element to open said valve means, a wire line extending through the tubing string and supporting said device, and wire line control means at the surface of the earth for selectively positioning said actuator abreast of said element for aifecting said valve, and cleared therefrom.

15. Gas lift control means as described in claim 14 in which said actuator device comprises a generally tubular body for running through the tubing string, a lever pivoted on said body, a plunger operatively connected to said lever for selectively expanding and collapsing said lever for actuating and clearing said element, and a datum pressure charged, expansible and collapsible chamber member operatively connected to said plunger and exposed to tubing pressure for controlling said lever in accordance therewith.

16. In combination with a well having a tubing string with a flow passage through the wall thereof and a gas pressured annulus, gas lift control means comprising normally closed valve means controlling said passage, an actuator element for said valve means exposed inwardly of said tubing, an actuator device slidable within said tubing and having a tubing pressure sensitive member, mechanism operatively connected to said member and selectively movable thereby to an operative position for actuating said element and an inoperative position to clear said element, a wire line support for said device extending from the surface through said tubing, and feed means at the surface for said wire line comprising a timer for periodically lifting said device to clear said actuator element and permit closing of said valve means.

17. The combination described in claim 16 in which said actuator device includes, further, mechanism ex tensible and retractible into and out of the latching engagement with the tubing wall responsive to predetermined tubing pressure conditions and said feed means includes means sensitive to the weight of said wire line i for causing lowering of said device when said latter mechanism is retracted from latching engagement with the tubing string.

18. Flow control means for a cased well including a tubing string having a flow passage in the wall thereof for conducting fluid from the well annulus into said string comprising normally closed valve means controlling said passage, an actuator element for said valve means exposed inwardly of said string, and a valve actuator device slidable within said string, said device having a tubing pressure sensitive member, mechanism operatively connected to said member and responsive to predetermined tubing pressure for movement into a position for actuating said element, means responsive to flow of fluid through said passage for moving said mechanism to a position to clear said element, and timed means for periodically returning said mechanism to said element actuating position.

19. Flow control means as described in claim 18 further including mechanism operatively connected to said pressure sensitive member for latchingly engaging the tubing wall adjacent said actuator element.

20. Flow control means as described in claim 19 in which said actuator devices includes plunger means upstream of said mechanism cooperable with fluid admitted through said flow passage to bodily lift said device away from said actuator element, thus permitting said valve to close.

21. Flow control means as described in claim 20 further including cooperating catcher structure in the well above said valve means and on said actuator device for holding said device in inoperative position when lifted therto.

22. Flow control means as described in claim 21 further including timed means for periodically releasing said device from said catcher structure.

References Cited by the Examiner UNITED STATES PATENTS 2,093,609 9/1937 Koen 103-24O 2,255,648 9/1941 Bryan 103232 2,431,751 12/1947 Hayward 1-66120 X 2,642,889 6/1953 Cummings 137-155 3,031,976 5/ 1962 Hodges 103232 X LAURENCE V. EFNER, Primary Examiner, 

1. THE COMBINATION WITH WELL PRODUCTION TUBING HAVING PORTS THROUGH THE WALL THEREOF AT INTERVALS THEREALONG OF A VALVE CONTROLLING EACH OF SAID PORTS AND A VALVE ACTUATOR DEVICE RECEIVED IN SAID TUBING AND NORMALLY MOVABLE THEREALONG PAST SAID VALVES, SAID DEVICE INCLUDING MECHANISM FOR ENGAGING AND OPENING SAID VALVES SELECTIVELY DURING MOVEMENT ALONG SAID TUBING AND MEANS OPERATIVE- 